Bridging plug



Nov. 18, 1952 G. F. TURECHEK ET A1.

BRIDGING PLUG 4 Sheets-Sheet l Filed April 20, 1946 9u 7 9 l 0 0 I 1 3 aw Waasfh ,9 a jww nl r a M 0o J 70a 5 M W. Mw av V a, mm//li/lzf/ v b1 m7. D im fnv/l Nov. 18, 1952 G. F. TURECHEK ETAL BRIDGING PLUG 4 Sheets-Sheet 2 Filed April 20, 1946 Nov. 18, 1952 G. F. TURECHEK ETAL 2,618,344

' BRIDGING PLUG Nov. 18, 1952 G. F. TURECHEK ET AL BRIDGINC PLUG 4 Sheets-Sheet 4 Filed April 20, 1946 E @Mw w me@ e www m E WM@ m v /JMW Genga' ByDa/lald muv;

Patented Nov. 18, 1952 Zlii TENT OFFICE BRIDGING PLUG George F. Turechek, Los Angeles, and Donald G. Moorhouse, South Gate, Calif., assignors to Lane-Wells Company, Los Angeles, Calif., a

corporation of Delaware Application April 2o, 1946, serial No. 663,662

' (or. 16s-i3) 18 Claims. 1

This invention relates generally to well packers and more particularly to bridging plugs and tools for setting bridging plugs and the like devices within well bore holes.

Bridging plugs are usually employed for the well known purpose of closing or sealing oli lower sections of a well bore hole. Such bridging or plugging operations are often employed, for example, when a lower zone in the well has ceased to be productive, or where the well bore hole has been drilled into water-producing measures or thief sands, or for any other such reason it is desired to plug back or close-off a lower zone and produce from a higher zone in the well. In such bridging operations it is usual practice first to position a bridging plug in the well bore hole at a point adjacent the top of the zone to be sealed oii, and then to place a suitable quantity of cement on top of the plug. However, heretofore, with the bridging plugs employed for this purpose, difficulties have been encountered in adequately anchoring a plug in the bore hole and securely maintaining the plug in the desired position during the cementing operation. If care was not exercised, the plug was often driven down by the weight of the cement placed on top of it. Sometimes the formation pressure below the bridging plug rose sufficiently to force the plug upward and thus displace the plug in the well bore hole from its proper setting position. In the cementi'ng operations heretofore employed in connection with the conventional type of bridging plugs, channeling through the cement placed in or on the bridging plug often occurred, caused by the production of fluid at the point of plugging or therebelow. Furthermore, with the conventional bridging operations heretofore employed, it was necessary to lower the bridging plug upon pipe or tubing, and nally to place the cement on the bridging plug also through tubing.

These operations heretofore employed were difficult, time-consuming and, for the reasons beforementioned, of uncertain eiiect and efficiency.

It is, accordingly, an object of this invention to provide a bridging plug which, when set in the bore hole, forms a fluid-tight seal and resists displacement by pressures either from above or below the setting point.

It is also an object oi this invention to provide a bridging plug capable of forming a fluid-tight seal with an irregularly-shaped surrounding bore hole.

It is a further Object of this invention to provide a bridging plug which will retain cement in non-channeling, sealing engagement with the walls of the surrounding bore hole.

It is a still further object of this invention to provide a bridging plug which may be rapidly lowered and positioned within the bore hole by means of a wire rope or cable which contains an electrical conductor through which the setting itrolled.

It is a still further object of this invention to provide a bridging plug of novel construction which is durable, eiicient, inexpensive, simple to operate, and which will remain securely positioned in the bore hole. l

It is a still further object of this invention to provide means for performing a combined bridging and cement plugging operation in one simple, quick operation.

These and other objects, advantages, and features of novelty will be evident hereinafter.

In the drawings which show by way of illustration, preferred embodiments of the invention, and in which like numerals designate the same or similar parts throughout the several views:

Figure 1 is an elevational view, partially in section, of the general assembly of the bridging plug and setting tool suspended in unset condition within a well bore hole.

Figure 2 is a detail view in longitudinal crosssection, of the setting tool portion of Figure 1.

Figure 3 is a detail view in longitudinal crosssection of the bridging plug portion of Figure l.

Figure 4 is an elevational view partially in cross-section of the bridging plug and a portion of the settingr tool as it appears in its initially set position within a Well bore hole.

Figure 5 is an enlarged detail view in longitudinal cross-section of the bridging plug portion of Figure 4.

Figure 6 is an elevational view partially in cross-section of the bridging plug and a portion of the setting tool in its iinally set and cemented position within a Well bore hole.

Figure '7 is a cross-sectional View taken line 1-1 of Figure 3.

Figure 8 is a cross-sectional view taken line 8-8 of Figure 3.

Figure 9 is a cross-sectional view taken line 9 9 of Figure 3,

Figure 10 is a cross-sectional view taken line Ill-I0 of Figure 3.

Figure 11 is a cross-sectional elevation of an alternative construction of the bridging plug as it appears in unset condition.

Figure 12 is a cross-sectional elevation of the alternative bridging plug of Figure 11 as it appears in the set condition within a well bore hole.

Referring now primarily to Figures 1, 2, and 3, the bridging plug portion of the tool is shown generally at I0 and the setting portion of the tool shown at ll, the bridging plug portion and the setting tool portion being coupled together by means of a quick detachable coupling or slip joint l2 which, when assembled in the runningin position as illustrated in Figure l, is held together in intercoupled position by means of shear pins I3.

Referring now primarily to Figures l and 3, the bridging plug portion of the tool comprises a generally cylindrical or tubular body I5 of somewhat irregular external diameter, which makes threaded connection at I6 at its upper end to a OIl 'check valve housing I1. The check valve housing I1, in turn, makes a relatively fluid-tight connection at the beforementioned detachable coupling I2 by Way of shear pins I3 with the lower end of the cement chamber 20 of the setting tool I I which will be hereinafter more fully described.

Surrounding the lower` portion of the bridging plug body I5 is a packing means for closing the annular space between the plug body and a surrounding well bore hole, comprising a, generally tubular or globular-shaped cementing bag 2| which, in its retractedor unfilled condition, is twisted and foldedrabout thepacker body as shown in Figures V1 and 3, such that its globular fullness is taken up to form a plurality of spiral folds which lie close to the packerbody.

The lower` end or neck opening ofV the cementingbag carries a suitable marginal beading 25 which is clamped around the lower end of the packer body I5 within a counterbored annular recess 26, the clamping being effected by means of a flared shoulder portion of a lower spider supporting body 21 which makes, at its upper end, threaded connection at 28 with the internal end portion of the packer body I5.

The upper end or neck opening of the cementtioned, locking the bag retainer 'fclla assembly 29 against movement on the plug body I5.

A shear pin 50 extending cross-wise through the plug body and through the central portion ance through the bore 58 in the upper innerl portion of the beforementioned spider supporting body 21. The lower end of the cylindrical member 51 makes threaded connection at 59 with a spider locking'hea'd 60. The spider locking head 60 is contained within the lower, enlarged bore ofthe body 21 which is closed at the lower end by means of a roundedguide cap'member 6I threaded thereto internally at 62. The locking ing bag 2I carries a marginal beading 35 simian inner sleeve member andan exterior clamping ring 3i which makes a snug sliding t at 32 over the shoulderedupper end ofr the said sleeve pins as shown at 34. The beaded end of the cementing bag neck is thus adapted to be clamped in a counterbored annular recess 36 formed between the lower ange 33 of the clampassembly 29 is restrained against both 'sliding and rotational motion upon the body I5 of the plug by a latching means 'comprising a pair of latch balls as shown at 38 which are retained in oppositely positioned holes 39 extending through the wall of the packer body I5 in such positions ,l that each ball extends into a detent formedin the inner surface of the collar3ll as shown at 49. The balls 38 thus, in the condition illustrated in Figure 3, serve as latches to restrain head 60 is thus normally suspended in locked position by means of the cylindrical member 51, tubular strut 54, and piston'valve 46 upon the shear pin 50, when the bridging plug is in the unset or retracted position as illustrated in Figure 3.

The lower'spider retainer body 21 is provided with a plurality of circumferentially spaced, radially directed slots extending from inside to outside thereof as best shown Vat 65 in Figures 3 and 7. Each slot is adapted to receive and to radially, pivotally support one each of the plurality of legs 66 of the spider assembly. Each leg of the spider assembly is formed with an external spike 61 carand is held in position there by means of suitable Tying a sharp point 68 at its outer extremity' Each leg also carries an integrally formed, inwardly extending tongue member 16 positioned at an obtuse angle to the spike and having an inner end face adapted to abut in latching en- 3 gagement with the outer cylindrical surface 1I of an annular shoulder or hub formed about the upper portion of the beforementioned locking head 60. The beforementioned abutment of the inner end faces of the tongue members 10 against 'the cylindrical surface 1I of the locking head hub serves to lock the legs 66 closed in their fully folded, retracted positions, as shown in Figure 3. A helical spring 12 surrounds the locking head 66 and, acting under compression between the a inner bottom surface of the guide cap 6I and the cementing bag retainer assembly 29 from y;

both axial sliding motion androtational movement with respect to the packer body I5.

Slidably retained within the cylindrical bore 45 of the bridging plug body I5 is a cylindrical, piston type, sliding valve 46 which, when the bridging plug is in theunset condition, as illustrated in Figure 3, covers a pair of oppositely positioned ports 41 and 48 which extend through the walls ofthe plug body I5. The upper limit of movement of the piston type Valve 46 is determined by a pair of inwardly extending stop pins 49 and, when the valve is in its uppermost position, as illustrated in Figure 3, the beforementioned latch balls 38 are retained by the upwardly extending skirtv portion of the Valve in the holes -39 inV outward `latching positions with respect to the Vdetents 40, thereby,l as beforementhe lower edges of the tongues 16 of the legs 66, serves to urge the spikes 61 into their opened position, as shown in Figure 5, against the restraining locking action hereinbefore described.

AA stop pin 16 extending through thewall of 'the bridging plug body I5 adjacent the upper end of the lower spider retainer body 21, serves to limit the downward movement of the valve 46 when it is forced to its open position, as hereinafter more fully described in connection with the operation of the apparatus.

Slidable axially on the outer surface of the upper portion of the bridging plug body I5, is an upper spider retainer ring 15. Pivotally supported by pivot pins 16 in a plurality of circumferentially spaced slots 11 located at the lower end portion of the said retainer ring 15 Vare a plurality of spider legs or spikes, as shown at 16. The lower end oi each of the spider spikes 'i6 is bevelled to a sharp point as shown at 19, and in the retracted position as shown in Figure 3, the spider legs or spikes are retained in closed position between an inner seating ring 80 xed to the plugbody by Screws 82 and an annular flange 8| extending upward from the beforementioned clamping ring member 3| of the bag retainer assembly 29.

The sp-ider retainer ring is urged axially downward with respect to the body I5 by means of helical spring 83 surrounding the body I5, and acting under compression between the upper channeled edge of said spider retainer ring 15 and the lower end of a lock nut 8d carried on a thread l5 and jammed against the lower end of the check valve housing I1. The pointed ends "e9 of the spider spikes 15 rest against a downwardly diverging conical surface 35 formed around the ring 80 so that under the downward force therethrough from the spring 33 acting through the retainer ring '15, the said spikes 18 will tend to slide at their bevelled ends upon the said conical surface 55 and to be forced outwardly against the inner cylindrical surface of the flange 8|. The beorementioned surrounding flange 5| thus serves to retain the spider spikes 18 against movement to open positions until released as hereinafter explained.

A plurality of wickers 85 are provided around the external surface of the body l5 into which a split, bevelled locking ring 93 carried in an internal groove in the upper spider retainer ring 15 is adapted to make locking engagement, as shown in Figure 5, when released to move downward under the force oi spring d3. Return movement of ring 53 and resultant retraction of the spikes 18 will thus be prevented.

A check valve ball 51 is retained within the lower chamber 33 of the check valve housing |1. A check ball stop is provided as shown at 9G upon which the check ball 81 is adapted to rest when in its open position, as indicated by dotted lines at 85.

An annular valve seat 9| is retained within a suitable, annular recess formed in the inner surface adjacent to and slightly below the necked portion S2 of the check valve housing l1, and upon which the check valve ball seats in its closed position, as shown in full lines at 81. The check ball 81 is preferably constructed of a material of sufficiently low density to be buoyant and float upward into the closed position as shown at 81, when the device is iilled with cementitious material, as hereinafter described.

Referring now primarily to Figures 1 and 2, the setting tool portion of the apparatus, as hereinbefore mentioned, comprises two main parts connected axially end to end comprising an upper weight housing or barrel 98 and a lower elongated, cylindrical cement chamber 2d. The chamber 2E! is normally attached at its lower end by means of the beiorementioned coupling I2 and shear pins 3 to the hereinbefore described bridging plug mechanism. Intercommunication is provided between the bore of the upper portion of the bridging plug body i5 and the lower portion of the bore of the chamber 20 through the beforedescribed check valve housing |1.

The upper end of the cement chamber body is threadedly connected at 95 and 56 through an intermediate sub-connector S1 to the lower end of the elongated weight housing barrel .'l.

The upper end of the weight housing barrel 98 is threadedly connected at 55 through suitable coupling apparatus to the lower end of a cable head |00, into which a suspending conductor cable |0| extends and maybe anchored in conventional manner, for example, as shown and described in Turechek 2,043,341. The conductor cable |0| may be any of the suitable conventional types of hoisting cables containing an internal, insulated conductor such as employed in connection with gun perforating operations; for example, those shown and described in Wells 2,043,400 and 2,043,401. The electrical conductor from the conductor cable |01 passes from the anchored ends of the cable through suitable insulating means and makes electrical contact with a contactor |52.

Intermediate the cable head |50 and the upper ends of the weight housing barrel 98 and making threaded connection respectively there-with at |04 and 05, is a weight barrel sub-connector |06, and electrical conductor rod |01 passes centrally through the sub-connector me through a suitable insulating bushing |58, and extends upward through a packing gland |59 into a cavity ||0 formed between the upper, inner portion of the sub-connector |55 and the lower end of the cable head |50.

A spring-pressed contact button serves to provide a quick detachable electrical contact between the terminal |02 of the conductor cable and the conductor rod l'l which passes downward through the sub-connector |56. The lower end of the conductor rod |01 terminates in an insulated button ||2 contained within a powder or cartridge chamber H3.

Any suitable arrangement for making suitable electrical connections between the cable head |00 and ignition means located in the powder chamber ||3 may be employed, for example, one such as shown and described in Quintrell 2,266,382 or Wells 2,076,307.

The cartridge chamber lf3 is contained within a weight supporting shackle ||5 which makes threaded connection at ||6 with a boss ||1 extending axially downward from the lower portion of the beforementioned weight barrel sub |06.

The lower end of the shackle |5 carries a clevis pin or bolt |25, over which a weight hook |2| extends. The hook |2| extends from the upper end of a cylindrical weight body |22 and serves to support a plurality of cylindrical weights within the barrel 98, the adjacent weights being hooked together end to end, as best illustrated at |25 in Figures 1, 4, and 6.

The lowermost weight in the weight cylinder 58 is provided with an axially positioned, downwardly extending, tapered shank |21 as best shown in Figure 2, which is adapted to seat within a correspondingly tapered socket |28 formed in the upper end of a plunger retainer body |29. A plunger I 30 made of rubber or other suitable material is retained by means of a bolt |32 in a socket |33 formed in the bottom end of the plunger guide body |28. The plunger is formed with an outwardly flaring skirt |35 which makes a slidable sealing engagement with the inner surfacev of the bore of the cement chamber 2li. A uted guide head |36 is threadedly attached at |31 to the lower end of the beforementioned plunger bolt |32, and together with the body |29, serves to guide and to maintain the plunger |30 in axial alignment within the cement chamber 20 as it is moved therethrough by means of the weights |22, as hereinafter more fully described. Chamber 2|) is provided with one or more plunger bleeder ports 20.

The weights |22 may be of any suitable construction adapted to withstand the tensile and compressive' forces to which they are subjected in the various stages of operation of the setting tool. The weights |22, however, are preferably constructed as shown with an external, tubular shell |40 extending from end toY end thereof. Hooks or alternate hooks and eyes may be attached to the opposite ends of the weights |22, as shown at |4| and |42 in Figure 1, these hooks and eyes being attached -at the end preferably both to the beforementioned tubular shell |49 and anchored to a central rod |45. The eyelet |2|, as best shown in Figure 2, is preferably formed as an upper extension of a socket |46 having outwardly extending flanges |41 adapted to be attached by suitable means, such as welding, to the upper end of the tubular shell |46. Longitudinally extending guide webs may be provided as shown at |48 radiating from the beforementioned socket |46. The socket |46 forms a recess in which a head |49 formed on the end of a central rod |45, is retained in recessed position. A plurality of perforate webs |50 welded to the rod |45 at spaced positions throughout its length, are provided to form reinforcing to the weight sections and to adequately bond with the metal with which the weight shell is lled. The weight shell comprising the space within the beforementioned tubular shell |40, is preferably lled with molten lead and allowed to solidify around the rod |45 and the webs |59, as shown at The lowermost one of the weights |22, instead of being provided with an eyelet or hook at its lower end as with the other weights, carries instead, a plug fitting |52 inserted within the end of the shell |46, and pin connected there as shown at |53.

The fitting |52 carries the tapered shank |21 hereinbefore described, which is adapted to transfer the downward pressure from the weights |22 to the plunger body |29.

A stop pin |54 is provided extending' across the lower end of the bore of the cement chamber 20 against which the plunger guide |36 comes to rest at the lower limit of the downward motion of the plunger assembly.

Referring now primarily to Figure 1l, in which an alternative construction of the bridging plug portion of the apparatus is illustrated, the body portionthereof comprises an upper, tubular body section |55 of stepwise irregular external diameter, adjustably connected through a threaded coupling at |56 and lock nut |51 with a lower tubular extension |58.

The upper end of the upper body portion |55 is shear pin connected as shown at |66, to the lower end of the cement chamber 2|] in an arrangement similar to that described in connection with Figures 1 and 2.

The intermediate portion of the body |55 is provided with an internal bore [6| of uniform diameter in which a cylindrical piston type valve |59 is retained in axial sliding fit. An upper, tubular extension of reduced diameter |60 of the valve |59 makes threaded connection at |62 with a downwardly extending tubular element |63 of a hollow plunger body |64,

A plurality of ports are provided through the wall of the piston valve |59 as shown at |61, and a fluid-tight communicating duct is thus provided from the said ports |61 to the cavity |69 within the plunger body |64 by way of the inner bore of the piston valve |59, the interior passages of the beforementioned interconnected tubular extension |66 and the plunger body |64.

Suitable packing rings are provided in annular grooves in the plunger, as shown at |12 to provide 8 fluid-tight sliding sealV between they plunger body |64 and the bore of thel lower end of the cement chamber 29.

In the unset condition of the bridging plug, as illustrated in Figure 1l, the axially movable assembly comprising the piston valve |59, tubular extension |66, tubular element |63 and plunger |64, is initiallyA maintained in its uppermost position by means of a pair of shear pins |13 which extend through the walls of the upper portion ofthe packer body |55 adjacent the upper end thereof and into the collared lower end of the lower portion |63 of the plunger body.

Contained within the cavity |69 of the plunger body 64, is a check ball Valve |15. The check ball Valve |15, as hereinbefore described in connection with the apparatus illustrated in Figure 3, is composed of a light-weight material, such as for example, Bakelite or other suitable plastic material, which will be buoyant in the cementitious fluid or cement slurry with which the apparatus is to be lled.' The check ball |15, when thus buoyed by the cement slurry contents of the apparatus, is adapted to seat in huid-tight sealing engagement with an annular packer ring |16 retained within an annular retainer recess in the valve seat |11. A plurality of radially positioned Webs |19 are provided in the lower, inner portion of the cavity |69 of the plunger |64 to receive the check ball |15 when it is in its lowermost, open position, as illustrated by dotted lines |86. When the check ball |15 is thus positioned in its open position upon the webs |19, downwardly owing fluid entering the top of the plunger through central openings |9| in the valve seat assembly, may pass around the check ball through the openings formed between the said webs |19 and flow downward into the passageilivay leading to the bore |16 of the piston valve A plurality of spaced packer rings set in annular recesses in the valve |59, as shown at |83, are provided for making a fluid-tight sliding seal between the piston valve |59 and the bore |6| of the bridging plug body |55.

A rod extends downward from its threaded connection |86 at the lower end of the piston valve |59 coaxially through the bore of the lower portion |58 of the plug :body and carries, threaded to its' lowermost end, a bushing |89 which, in turn, carries externally threaded thereon at |90 a spider locking head |9| of a construction similar to that illustrated at 66 in Figure 3. The lower end portion of the body |58 into which the locking head |9| extends, is of slightly enlarged diameter and carries a plurality of slots extending radially therethrough similar to the arrangement hereinbefore described in connection with the corresponding portion of the device in Figure 3. Each of these radial slots is adapted to pivotally support a spider leg as shown at 66. Each spider leg comprises an outer spike portion 61 and an integrally formed inwardly extending tongue portion 10. The inner end faces of the tongue portions 10 of the spikes each make locking engagement with a cylindrical, shouldered surface at the top portion of the locking head 9| in the same manner as that hereinbefore described in connection with the corresponding apparatus illustrated in Figure 3.

A pair of oppositely positioned outlet ports and |96 are provided through the intermediate portion of the bridging plug body |55, said outlet ports |95 and |96 being adjacent the piston type valve |59, such that they are closed thereby when ,9` the valve |59 is in its uppermost position as illustrated in Figure 11.

Surrounding the lower portion of the bridging plug body |55 and the lower extension |58 thereof, is a packing means comprising a generally tubular or globular shaped cementing bag |98, similar to bag 2| hereinbefore described in connection with Figures 1 and 3 which, in its retracted or unfilled condition, is twisted about the tubular body such that it forms a plurality of spiral folds which lie close to the packer body.

The lower neck opening of the cementing bag |98 may be attached to the exterior of the lower body portion |58 adjacent the outer retainer assembly by any suitable means such as, for example, that hereinbefore described in connection with Figure 3. The lower neck of the cementing bag may, however, be satisfactorily attached to the bridging plug body by means of an inwardly and upwardly extending cuil-like fold as shown at |99, placed in a shallow, annular-shaped recess and bound in place by suitable clamping rings or a plurality of turns of wire, as illustrated at 259.

The upper end of the cementing bag |98 may be similarly attached to a ring member 292 which is rotatably retained upon the plug body between la lower raised shoulder 203 and the shoulder formed at the lower end of a plurality of longitudinal a plurality of corresponding slots 295 extending through the upper portion of the said plug body The upper end of the ring 292 is provided with a flange 295 of slightly increased diameter through which a plurality of longitudinally extending grooves have been formed, each groove being adapted to receive the inner edge of -a spider spike, as shown at 291, when the spikes of the spider are retracted in their closed positions, as illustrated in full lines in Figure 11. l

A downwardly extending spider retainer collar 2|9 is threaded at 2|| onto the upper end of the plug body |55. The plug body is formed with an upper section of slightly increased diameter at the point carrying the beforementioned threads 2H, forming thereby a shoulder 2|2. The retainer collar 2|0 extending downward from the shoulder 2|2 forms inside thereof an elongated, annular-shaped recess which houses a helical spring 2|3. The helical spring 2|3 is adapted to act under compression between the shoulder 2|2 and the upper edges of the inwardly extending tongues 220 of the spider legs, tending to urge them pivotally into expanded position, as shown in Figure 12 and as hereinafter more fully described in connection with the operation of the apparatus. v

The lower end portion of the spider retainer collar 2|9 is provided with a plurality of slots as shown at 2|4, registering with the beforementioned slots 295 which extend through the body |55. A plurality of spider legs 2|5 are pivotally supported in the slots 2 I4 by suitable means such as that illustrated at 2|5. Each spider leg, as -hereinbefore described in connection with the lower spider of Figure 11 and the lower spider of Figure 3, is provided with an outer pointed spike member 2|8,and an inner integrally formed, an- Ygularly-directed'tongue member 22D. The inner end face of each* tongueA member 2291s adapted to abut, when in the retracted position, against a cylindrical surface V22| formed by a shouldered section intermediate the Vpiston valve |59 and its 19 upper tubular'extension portion |99 of reduced diameter.

As hereinbefore mentioned, the spiral spring 2 I3, acting under compression against the shoulder 2|2, app-lies a force downward against the top edges of the spider tongues 229, tending to rotate them about pivots 2 I5, to move the spikes 2|9 radially outward into open position, as illustrated in Figure 12.

Each of the points of the spikes 2 I8 of the upper spider is preferably covered or coated with a protective covering of a suitable material such as a soft metal or plastic, as illustrated at 223.

The operation of the apparatus of Figures 1-10, inclusive, is as follows:

First, in preparation of the apparatus for 0D- eration and prior to lowering it into a well, the cement chamber 29 is disconnected from the weight barrel 98 at the threads 99, at the upper end of the sub-connection 91. The cement chamber 20 and the depending bridging plug portion I9 are then suspended vertically by suitable means which may be conveniently clamped around the annular recess formed in the mid-portion of the sub 91. The cement chamber 20 and the bridging plug body from the top of the piston valve d6, including the space within the check valve chamber 88 are next iilled with a cernentitious material, such as for example, a slurry of a quick setting Portland cement or other suitable fluid or plastic cementitious material by means of which it is desired to bridge the well bore hole.

After having lled the bridging yplug and the cementing chamber 2G up to a point close to the bottom threaded joint of the sub 91, the plunger assembly |29 is placed in the top thereof and pushed down upon the top of the cement.

Next, the weight barrel 98 containing the weights |22 suspended by means of the shackle l5, all of which may be suspended by the conductor cable I9 is lowered onto the top of the cement chamber connecting sub 91, the tapered shank |21 of the lowermost weight inserted in the tapered socket |28 in the plunger body |29 and joint at threads 95 then made up. The tool then has the appearance illustrated in Figure 1 and is ready for lowering to the desired position within the bore hole to be bridged.

When the assembled setting tool and bridging plug have been lowered by the cable IDI to the desired level in the bore hole at which it is to be set, as shown in Figure l, current is passed from a suitable source, such as that employed in gun perforating equipment, through the conductor cable |9| and by way of contact terminals |92 and I9, and conductor rod |01 to an ignition lament H li contained within the powder charge or cartridge in the powder charge cavity H3 in the weight suspending shackle H5. The resultant combustion or explosion of the powder or cartridge contained in the cavity ||3 breaks the shackle i5 at the intermediate section of reduced diameter surrounding the powder chamber, thereby releasing the weights |22. The weights |22 thus released from suspension move downward applying force through the shank |21 and through the body |29 to the plunger |39 and thence to the body of cement slurry contained therebelow in the cement chamber 29.

The pressure thus applied to and built up in the body of cement slurry in the cement chamber 25, is communicated through the interior of the setting tool body to the top of the piston type valve 45, which is initially in its uppermost position, as shown' in Figure 3. When the pressure gagement with the outer openings |95 and |98 through the bridging plug body |55, after which the cement slurry is free to flow downward from the cement chamber 20 through the piston valve |59 out through the ports |61 and openings |95 and |96 into the space within the packer bag |98, expanding it into engagement with the Walls of the bore hole and the inner edges of the upper and lower spider spike assemblies as shown in Figure 12. The opening movement of the spider legs 2|8 Will be assisted by the action of the helical spring 2|3.

After the bridging plug has been anchored in the bore hole and the packer bag filled as illustrated in Figure 12, sufficient upward tension is then taken in the conductor cable, as hereinbefore mentioned in connection with Figures 1-10, inclusive, to shear the pins |66 thereby allowing the setting tool portion of the apparatus, including the weight barrel 98 and the cement chamber 20 to be withdrawn from the bridging plug and hoisted out of the bore hole. The balance of the cement slurry contained within the cement chamber will then be emptied upon the top of the bridging plug in the same manner as illustrated in Figure 6.

Advantages of the apparatus of Figures 11 and 12 over those previously shown and described reside in the smaller diameter to which the packing bag |98 may be folded and retained, and also in the greater pressure which may be exerted to actuate the setting apparatus by the plunger |64 which occupies the full diameter of Vthe cementing chamber.

The packer bags illustrated at 2| and |98 in the drawings may be made of any suitable flexible material having the required tensile strength but the preferred material and construction found to be particularly well suited to this purpose is a bag formed with a spun glass fabric layer or a plurality of overlying or overlapped layers or laminations of spun glass fabric impregnated with natural or a suitable synthetic rubber and vulcanized in a manner similar to that employed in the formation of automobile tires.

The beading in the end necks of the packer bag may also be formed in a manner similar to that employed for forming the bead around a tire and may contain an annular reinforcing core of wound wire, or of cords of spun glass, rayon or the like material vulcanized within a cuff-like fold formed by folding back over such reinforcing core a short length of the end portion of the bag neck.

Any required number of weights of the type shown at |22 in Figures 1, 2, 4, and 6 may be employed as required to apply sufficient pressure to the cementitious uid in the cement chamber 20. It has been found that about 4 weights each weighing 245 lbs. each acting, as illustrated, upon a plunger of 3.75 inches in diameter and thereby producing a net pressure of approximately '72 lbs. per square inch in the cement chamber allowing for buoyancy of the drilling fluid, will be adequate for expelling the ordinary cement slurry from the cement chamber, actuating the piston type valve and associated spider releasing mechanisms, and for lling and rmly inflating the packer bag, under usual fluid-containing, well bore hole conditions. For example, employing a bridging plug having a body of 4 inches in diameter and a packer bag approximately 24 inches long between necks and approximately 10% inches in diameter in -its fully inflated condition, has

14 been found to form a rm seal with a surrounding bore hole of 9% inches in diameter, under the cement pressures hereinbefore specified.

The bridging plug body may be made of cast iron, the several springs and the piston valve mechanism of brass and the spider legs or spikes of malleable cast iron so that the bridging plug may be drilled-up if desired. Other suitable materials may be employed, if desired, to suit particular obtaining conditions. For example, under some conditions, it has been found desirable and satisfactory to construct the body portions of the bridging plug of a thermo-setting plastic material preferably containing a fibrous reinforcement material.

It is to be understood that the foregoing is illustrative only and that the invention is notl limited thereby, but may include various modifications and changes made by those skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

We claim:

l. A bridging plug comprising: a body; a flexible bag attached to and surrounding said body; a fluid chamber connected with said body and in communication with the inside of said bag; a plunger slidable in said chamber and adapted to apply pressure to fluid therein to expel fluid therefrom into said bag; a housing connected to said chamber; a plurality of weights in said housing; suspension means initially toA support said weights in said housing; means coupling said weights to said plunger; and means to release said weights from said suspension means to apply force to said plunger to expel fluid from said housing into said bag.

2. A bridging plug setting tool comprising: a iiuid chamber; a plunger sliolable axially in said chamber and adapted to increase the pressure therein to expel fluid therefrom; an elongated housing attached end to end in axial alignment with said chamber and in communication therewith; conductor cable means for suspending said uid chamber and housing in a well bore hole; a weight in said housing; means to suspend said Weight in said housing against axial movement therein; means to couple said weight to said plunger; and explosive means electrically controlled through said conductor cable to break said suspension means to release said weight to m'ove said plunger in said chamber.

3. A bridging plug setting tool comprising: a fluid chamber; a plunger slidable axially in said chamber and adapted to expel fiuid therefrom; an elongated housing attached end to end in axial alignment with said chamber and in communication therewith; conductor` cable means for suspending said fiuid chamber and housing in a well bore hole; a weight in said housing; releasable means to suspend said weight in said housing against axial movement therein; means to couple said weight to said plunger; and means electrically controlled through said conductor cable to actuate said releasable suspension means to release said weight to move said plunger in said chamber.

4. A bridging plug setting tool comprising: a uid chamber; a housing connected to said chamber; a Weight in said housing; releasable means connected to said housing to support said weight in said housing against axial movement therein; means to actuate said weight supporting means to release said weight for movement in said housing; and means connected with said weight and aplasta l operativeby motion of'said Weight to vary the displacement of said chamber toV force fluid from saidchamber; and means to detachably couple said chamber to a bridging plug;

5. In a bridging plug, formation gripping means comprising: a substantially cylindrical body; a pair of oppositely facing, axially spaced' formation gripping spiders mounted on said body, a formation engaging, flexible bag surrounding said body intermediate said spiders, said spiders each comprising a plurality. of circumferentially spaced spikes each pivotally attached adjacent one end thereof to said' body, Vsaid spikes being' adapted when retracted, to 'lie in paral1e1,`side by side circumferentially spaced positions about said body and when extended, to project outward from said body at an angle to the axis of saidisupport in circumferentially spaced, radially directed planes intersecting the axis of said support, said spikes being' thereby adapted when thus pivoted to extended positions to penetrate the wall of a surrounding bore hole, and thereby to resist axial motion of said body in either direction in said bore hole; resilient means urging said spikes into extended positions; means to lock. said spikes in retracted" positions; means to. inflate said bags; and means to actuate, said` locking meansl to re-` lease said spikes to extendedfpositions.

6. InV av bridging plug, apparatus according to claim 5 in which the-means to actuate said locking means andmeans'to inflate saidl bag are actuated'by a common VluidY pressure means associated'vvith said body.V

7.. A' bridging plug comprising: a body; a pair of spaced apart, oppositely positioned, retractable formationV gripping means on Vsaidbody; a flexible bag attached.' to and surrounding said. body intermediate saidgripping means; means to retain said bag in deflated and closely retracted position aroundv said body; means to' retainV said formation gripping means; in retracted position oncsaid body; a closed-fluid reservoir associated with said4 body; means in saidreservoir to apply pressure. tov fluid in said reservoir means Vto Vcon'- duct uidt under pressurel from said' reservoir' tov the-inside'of said bag andimeans actuated bythe thus applied-pressureofsaid fluid to releasesn'dV formation ,gripping means and said bagletaining means to permit saidi bag,v t'o beinfiated-bysaid uid.

8. A bridging plug comprising: albody; a flexible bag attachedto and surrounding said: body; releasable means to' retain said bag indeated and closely retracted position aroundxsaid" body; a closed fluid reservoir associated with said body means in said' reservoir to apply pressureto fluid in said reservoir; meansV to conduct fluid under pressure from said reservoir to thek insideof said bag; and means actuated by the thus applied' pressure of said fluidk to releasesaidretaining means to permit said/bag tobe inilated-by-said fluid. Y

9. A lbridging plug comprising: a-closed tubular body; apair of spaced,` oppositelyy positioned; formation gripping spiders onsaid body,V said formation' gripping spiders' being adapted to move! from closed to opened formation gripping posi-` tions; a flexible bag surrounding saidbody intermediate said spiders, said bag beingsealed at its opposite ends to said body atfpoints adjacent said gripping spiders; releasable y*means initially-gto re tain said bag in retracted position closely surrounding saidbody; afpassage providinglcom- Y munication between the-,inside of said bag andv theinterior'ofsaid body; achamber communicating With the inside of said body ;lapressure aci' tuated lvalve in said body normally closing-said passage, said valve being adaptedY to be opened upon development of a predetermined pressure in said chamber; a lock for retaining said formation gripping spiders in closed positions; means associated with and actuated by movement of said valve to release said lock; means associated with said valve and actuated by movement thereof to actuate said releasable means to release said bag from its retracted position; and means in said chamber for expelling nuid from said chamber under pressure through said body and said passage into said bag.

10. A bridging plug comprising: a tubular body; a pair of'spaced, oppositely positioned, retractable formation gripping spiders on said body, said formation gripping spiders being adapted to be moved between closed and opened positions; a exible bag surrounding said body intermediate said gripping spiders, said bag being sealed at its opposite ends to said body at points adjacent said gripping spiders; a passage providingcommunication between the inside of said basr and the interior of said body; a closed chamber' c'ommunicating with the said interior of said body; a pressure actuated valve in said body normally closing said passage, said valve being adapted to be opened upon development of a predetermined pressure in said chamber; a releasable lock for retaining said formation gripping spiders in closed positions; means actuated by movement of said valve to release said lock; means to move said formation gripping spiders from closed to opened positions upon releasev of saidV lock; and means in said chamber for expelling iluid from said chamber under pressure through. said body and said passage into' said bag.

11. A bridging plug comprising: Va tubular body; a pair of axially spaced, o'ppositely positioned, retractable formation gripping spiders on saidv body, said formation gripping spiders' b'eing adapted to be moved from closed to open position; a flexible bag surrounding said body intermediate said gripping spiders, said bag being sealed at its opposite ends to said body at points adjacent said gripping spiders; a passage' providing communicationA between' the inside' of saidbag andthe interior of said body; a cl'o's'e'dl chamber communicating with theinterior of said body; apressure actuated Yvalve inv said body normally closing said passage, said valvebeing adapted to be opened upon development of a predetermined pressure in said chamber; a rele'asable' l'o'ckfor retaining said formation gripping spiders in closedv position; means actuatedby'movement of said valve to release saidlock to permit said spider-stomove to 'opened positions; and meansv bagl and in the interior of said-body; a closed chamber c'ommunicatingfvvith theinterior of said body; a pressure" actuated -valve =in saidE bodyfnormally closing; said passage,-saidvalve'being adapted to beopened upon development of a prede'- f t'ermined pressure inf'said chamber; areleasable lock for retaining said formation gripping means in retracted position; means actuated by movement of said valve to release said lock; and means in said chamber for expelling fluid from said chamber under pressure through said body and said passage into said bag.

13. A bridging plug comprising: a tubular body; a pair of spaced, oppositely positioned, retractable, formation gripping means on said body; a flexible bag surrounding said body intermediate said gripping means, said bag being sealed at its opposite ends to said body at points adjacent said gripping means; a passage providing communication between the inside of said bag and the interior of said body; a closed chamber communicating with the interior of said bodv; a pressure actuated valve in said body normally closing said passage, said valve being adapted to be opened upon development oi a predetermined pressure in said chamber: and means in said chamber for expelling fluid from said chamber under pressure through said body and said passage into said bag.

14. A bridging plug, comprising: apparatus according to claim 8 in which the said releasable retaining means to retain said bag in deflated, closely retracted position around said bodv includes a collar rotatable upon a portion of said body; means forming a iiuid tight attachment of one end opening of said bag to said collar whereby said end of said bag mav be rotated with said collar with respect to the other end of said bag: means to restrain said collar from rotation with respect to said body: and in which the said means to release the said retaining means includes means to release said collar for rotation about said body.

15. A bridging plug comprising: a fluid chamber; a plunger slidable axiallv in said chamber and adapted to increase the pressure therein and to expel uid therefrom: an elongated barrel attached end to end in axial alignment with said chamber and in communication therewith; conductor cable means for suspending said barrel and chamber in a well bore hole: a weight in said barrel; means initially to suspend said weight in said barrel against axial movement therein; means to couple said weight to said plunger to transfer axial movement of said weight to said plunger when said weight is released for axial movement in said barrel: explosive means electrically controlled through said conductor cable to break said suspension means to release said weight to move said plunger in said chamber: a tubular body communicating with said chamber: a pair of spaced, oppositely positioned formation gripping spiders on said bodv. said formation gripping spiders being adapted to be moved from closed to opened formation grippingr positions: a flexible bag surrounding said bodv intermediate said spiders, said bag being sealed at its opposite ends to said bodv at points adjacent said gripping spiders; releasable means initially to retain said bag in retracted position closely surrounding said body; a port providing communication between the inside of said bag and the interior of said body: a valve in said body adapted initially to close said port and movable to open said port in response to pressure in said chamber; a releasable lock for retaining said formation gripping spiders in closed position; means carried by said body and actuated by movement of said valve to release said lock to free said spiders to move into opened positions; and means associated with said valve and actuated by movement thereof to release said bag from its retracted position.

16. A bridging plug comprising: a body having a fluid passageway therein; a flexible bag atta-ched to and surrounding said body; 4a port leading from the inside of said bag to the iiuid passageway in said body; a uid chamber connected with said body and in communication With the said fluid passageway therein; a plunger slidable in said chamber and adapted to apply pressure to fluid therein to expel uid therefrom through said passageway and said port into said bag; a housing connected to said chamber; a plurality of Weights in -said housing; suspension means initially to support said weights in said housing; means coupling said Weights to said plunger; and means to release Isaid Weights from said suspension means to apply force to said plunger to expel uid from said chamber into said passageway in said body.

17. A bridging plug comprising: a hollow body; a pair of spaced, oppositely positioned, formation gripping means on said body, movable between retracted and extended formation gripping positions; resilient means to urge said formation gripping means into extended formation gripping positions; releasable means to retain said formation gripping means in retracted positions; a flexible bag attached to and surrounding said body intermediate said oppositely postioned formation gripping means; .and means responsive to iiuid pressure within said hollow body for inflation of said bag, to actuate said releasable means to release said formation gripping means for movement to extended formation gripping positions.

18. A bridging plug comprising: an elongated body; a pair of spaced, oppositely positioned, formation gripping means on said body; a flexible bag surrounding said body intermediate said gripping means, said bag being ysealed at its opposite ends to said body Iat points adjacent said gripping means; a passage providing communication between the inside of said bag and the interior of said body; a closed chamber communicating with the interior of said body; fluid pressure generating means in said chamber operative for expelling fluid from said chamber under pressure through said body and said passage into said bag; means restraining said iiuid pressure generating means from operating to expel fluid from said chamber; and means to release said restraining means to permit said pressure generating means to operate.

GEORGE F. TURECHEK. DONALD G. MOORHOUSE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,342,927 Ruthven June 8, 1920 1,497,629 Baker June 10, 1924 1,549,168 Townsend Aug. 11, 1925 2,050,970 Hughes Aug. 11, 1936 2,053,448 Starr Sept. 8, 1936 2,207,448 Ashbrook July 9. 1940 2,229,635 Boynton Jan. 28, 1941 2,248,908 Phillips July 8, 1941 

